William denham grimshaw



(No Model.)

W. D. GRIMSHAW. MECHANICAL STOKER.

lgicegted Mar. 8, 1898.

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IVILLIAM DENHAM GRIMSHAVV, OF ACGRINGTON, ENGLAND.

MECHANICAL STOKER.

SPECIFICATION forming part of Letters Patent No. 600,419, dated March 8, 1898.

Application filed October 12, 1897. fierial No. 654,969. (No model.) Patented in England July 9, 1894,1T0. 13,241, and in India June 3,1896,N0. 241.

To all whom it may concern:

Be it known that LWILLIAM DENHAM GRIM- SHAW, a subject of the Queen of Great Britain, residing at Accrington, in the county of Lancaster, England, have invented new and useful Improvements in or Applicable to Me chanical Stokers, (for which I have obtained British Patent No. 13,21, dated July 9, 1894, and Indian Patent No. 24.1 of 1895, dated June 3, 1896,) of which the following is a specification.

This invention relates to improvements upon that class of mechanical stokers for which British Letters Patent were granted to me hearing date the 28th day of December, 1891, No. 22,509.

The invention will be readily understood from the following description on reference to the accompanying drawings, of which- Figure 1 is a front elevation, partly in sec tion, of my improvements shown applied to so much of a furnace-front as is necessary to illustrate the application of my invention. Fig. 2 is a horizontal section through the fanboX. Fig. 3 shows in transverse section and partial plan one of the rakes and the tie-bars hereinafter described. Fig. 4: shows the midfeather and one directing-plate detached.

According to my present invention, instead of using three fans and three fan-boxes, as mentioned in the specification of the Letters Patent above referred to, I propose to use two fans a a, both of the same diameter and working in one and the same fan-box b and fixed side by sideupon the same shaft 0, the two fans a a being placed at right angles to each other, as shown by Figs. 1 and 2. Opposite to the mouth of the fan-box Z) I have two directing-plates (Z d, (see Fig. 2,) which are so hinged as to be adjustable on a central pivot e by means of screwed rods f f and levers f the fired casting g for the said hinge being made with a tapered plate or mid-feather g (see Fig. 4,) which protects the hinge from the coal and divides the stream of the latter against the two directing-plates (,Z and d.

In a casing 71, placed between the hopper h and the fan-box b, are two rakes 7:; it, which are connected together by tie-bars 76X and have a Very slight to-and-fro motion given to themsay about five-eighths of an inch-and as they both impel the coal or fuel toward a single central opening b at the top of the fan-box b there are two impulses given to the coal at each revolution of the worm-wheel or crank-wheel m and crank or eccentric m. It will therefore be evident that one or other of the rakes 7c 7c is always feeding the central orifice b (one advancing as the other recedes,) and hence there is a continuous supply of fuel given to the fan-box b, and as the fans a a are (as before stated) set at right angles to each other they further assist in making the supply of fuel to the fire continuous and even.

In order to prevent the coal from becoming choked in the hopper-bottom 7%, I make in the latter two openings, (see Fig. 1,) one in front of each rake, which not only being divided but also being larger in area than the single opening hitherto employed, will be much less liable to become choked, and even if this should happen to one it is very improbable that they would ever both become choked at one and the same time, and therefore the supply of fuel would never be likely to cease altogether, as might be the case were only one opening to be employed.

I claim as my invention- 1. The combination of fan-box having central inlet with double feed-rake, two fans and adjustable directing-plates on vertical pivot at the center of the fan-box outlet, substantially as hereinbefore described.

2. The combination of a fan-box having a central inlet, and a double feed-rake, with two openings, in front of each rake, as and for the purpose set forth.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

WILLIAM DENHAM GRIMSIIAW.

\Vitnesses:

FREDERICK WILLIAM GREENWOOD, JNo. HUGHES. 

